Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended
Mar. 31, 2019	Dec. 31, 2018
Income Tax [Line Items]
Unrecognized tax benefits	$ 4,400,000	$ 4,400,000
Changes in unrecognized tax benefits	0	$ 0
Reasonably possible amount of unrecognized tax benefit that could reverse in the next twelve months	$ 100,000
SafeOp Surgical, Inc.
Income Tax [Line Items]
Effective income tax rate	(0.24%)
Federal statutory income tax rate	21.00%

Income Tax [Line Items]

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Amount of decrease reasonably possible in the next twelve months for the unrecognized tax benefit.

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Amount of unrecognized tax benefits.

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Amount of increase (decrease) in unrecognized tax benefits attributable to uncertain tax positions taken in tax returns.

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